Mechanical polyolefin recycling process

A mechanical polyolefin recycling process, comprising, in the given order:

• a) providing a precursor mixed plastic recycling stream (A);
• b) sieving the precursor mixed plastic recycling stream (A) to create a sieved mixed plastic recycling stream (B) having only articles with a longest dimension in the range from 30 to 400 mm;
• c) sorting the sieved mixed plastic recycling stream (B) by means of one or more optical sorters wherein the sieved mixed plastic recycling stream (B) is at least sorted by colour and optionally also by polyolefin type and/or article form, thereby generating one or more single-colour sorted polyolefin recycling stream(s) (C) and a mixed-colour sorted polyolefin recycling stream (CM), wherein each of the one or more single-colour sorted polyolefin recycling stream(s) (C) and the mixed-colour sorted polyolefin recycling stream (CM) are subjected separately to steps d) and beyond;
• d) shredding the sorted polyolefin recycling stream (C or CM) to form a flaked polyolefin recycling stream (D);
• e) washing the flaked polyolefin recycling stream (D) with a first aqueous washing solution (W1) without the input of thermal energy, thereby generating a first suspended polyolefin recycling stream (E);
• f) removing at least part of the first aqueous washing solution (W1) from the first suspended polyolefin recycling stream (E) to obtain a first washed polyolefin recycling stream (F);
• g) washing the first washed polyolefin recycling stream (F) with a second aqueous washing solution (W2) thereby generating a second suspended polyolefin recycling stream (G), wherein sufficient thermal energy is introduced to the second suspended polyolefin recycling stream (G) to provide a temperature in the range from 65 to 95° C. during the washing;
• h) removing the second aqueous washing solution (W2) and any material not floating on the surface of the second aqueous washing solution from the second suspended polyolefin recycling stream (G) to obtain a second washed polyolefin recycling stream (H);
• i) drying the second washed polyolefin recycling stream (H), thereby obtaining a dried polyolefin recycling stream (I);
• j) optionally separating the dried polyolefin recycling stream (I) into a light fraction and a heavy fraction polyolefin recycling stream (J);
• k) further sorting the heavy fraction polyolefin recycling stream (J) or, in the case that step j) is absent, the dried polyolefin recycling stream (I) by means of one or more optical sorters sorting for one or more target polyolefins by removing any flakes containing material other than the one or more target polyolefins, yielding a purified polyolefin recycling stream (K);
• l) Optionally melt extruding, preferably pelletizing, the purified polyolefin recycling stream (K) to form an extruded recycled polyolefin product (L);
• and
• m) optionally aerating the recycled polyolefin product (L) or, in the case that step l) is absent, the purified polyolefin recycling stream (K) to remove volatile organic compounds, thereby generating an aerated recycled polyolefin product (M), being either an aerated extruded recycled polyolefin product (M1) or aerated recycled polyolefin flakes (M2),
• wherein the order of steps l) and m) can be interchanged, such that the purified polyolefin recycling stream (K) is first aerated to form aerated recycled polyolefin flakes (M2) that are subsequently extruded to form an extruded aerated recycled polyolefin product (M3).